Rugose coral diversifications and migrations in the Devonian of Australasia

2001 ◽  
Vol 15 (1-2) ◽  
pp. 61-76 ◽  
Author(s):  
Yong‐Yi Zhen ◽  
Anthony J. Wright ◽  
John S. Jell
Keyword(s):  
Rugose Coral

Microborings and growth in Late Ordovician halysitids and other corals

1993 ◽  
Vol 67 (6) ◽  
pp. 922-934 ◽  
Author(s):  
Robert J. Elias ◽  
Dong-Jin Lee
Keyword(s):  
Growth Rate ◽  
Linear Growth ◽  
Inverse Correlation ◽  
Weight Percent ◽  
Late Ordovician ◽  
Coral Growth ◽  
Linear Growth Rate ◽  
Skeletal Density ◽  
Rugose Coral ◽  
Endolithic Algae

Microborings in the Late Ordovician tabulate corals Catenipora rubra (a halysitid) and Manipora amicarum (a cateniform nonhalysitid) and in an epizoic solitary rugose coral differ from nearly all of those previously reported in Paleozoic corals. These microborings were formed within the coralla by endolithic algae and fungi located beneath living polyps. Comparable structures in the Late Ordovician tabulate Quepora ?agglomeratiformis (a halysitid) represent algal microborings, not spicules, and halysitids are corals, not sponges as suggested by Kaźmierczak (1989).Endolithic algae in cateniform tabulates relied primarily on light entering through the outer walls of the ranks rather than through the polyps; lacunae within coralla permitted appropriate levels of light to reach many corallites. The direction of boring was determined by corallum microstructure and possibly also by the distribution of organic matter within the skeleton. There is an apparent inverse correlation between boring activity and coral growth rate.The location and relative abundance of pyritized microborings within calcareous coralla can be established quantitatively and objectively from electron microprobe determinations of weight percent sulfur along appropriate traverses of the coral skeleton. The distribution of such microborings in Catenipora rubra and Manipora amicarum is comparable to algal banding in modern corals; this is the first report of such banding in the interiors of Paleozoic corals. Change in the intensity of boring within each corallum was evidently a response to variation in the linear growth rate of the coral, or to fluctuation in an environmental factor (perhaps light intensity) that could control both algal activity and growth rate in these corals. Change in the algal boring intensity and linear growth rate of the coral was generally but not always seasonal and usually but not invariably associated with change in the density of coral skeletal deposition.Cyclic bands of boring abundance maxima within fossil colonial corals provide a measure of annual linear growth comparable to the widely accepted method based on skeletal density bands. Algal bands are more sporadically developed than density bands within and among coralla, thus increasing the difficulty of interpretation. Fluctuations in the abundance of algal microborings apparently provide a detailed record of changes in the linear growth rate of colonies and of individuals within colonies. Combined analyses of microboring abundance and skeletal density will contribute significantly to our understanding of the biological and environmental factors involved in endolithic activity and coral growth.

A rugose coral – bryozoan association from the Lower Devonian of NW Spain

2019 ◽  
Vol 530 ◽  
pp. 271-280 ◽  
Author(s):  
Consuelo Sendino ◽  
Juan Luis Suárez Andrés ◽  
Mark A. Wilson
Keyword(s):  
Lower Devonian ◽  
Nw Spain ◽  
Rugose Coral

Early Silurian carbonate platforms in the Appalachian orogenic belt: the Sayabec – La Vieille formations of the Gaspé–Matapédia basin, Quebec

1992 ◽  
Vol 29 (4) ◽  
pp. 704-719 ◽  
Author(s):  
Denis Lavoie ◽  
Pierre-André Bourque ◽  
Yvon Héroux
Keyword(s):  
Microbial Communities ◽  
Sea Level ◽  
Carbonate Platforms ◽  
Northern Margin ◽  
Lime Mud ◽  
Rugose Coral ◽  
Mud Flat ◽  
First Occurrence ◽  
Appalachian Orogen ◽  
Siliciclastic Sediments

The coeval Early Silurian (late Llandoverian to late Wenlockian) Sayabec and La Vieille formations represent the first occurrence of shallow-water platformal limestones and reefs in the Paleozoic sequence of the Gaspé Belt of the northern Appalachians. Both units display very similar fades, representing laterally well-zoned, south-dipping carbonate platforms with four parallel depositional belts. These, from nearshore to offshore, are (i) a peritidal mud flat dominated by microbial communities (laminites, stromatolites, thrombolites, oncolites); (ii) a low knob reef rim built by skeletal metazoans (corals, bryozoans, stromatoporoids), skeletal calcareous algae, and microbial communities; (iii) a well-sorted lime sand belt; and (iv) a deeper water nodular lime mud belt supporting a tabulate and rugose coral, stromatoporoid, skeletal algae, and large-shelled brachiopod biota. The two platforms developed at the margin of the Quebec Reentrant and St. Lawrence Promontory in the Gaspé Belt of the northern Appalachian Orogen. It is not clear whether they were parts of a single continuous platform stretching along the northern margin of the Gaspé Belt or two separate platforms occupying distinct tectonic blocks. The development of the Sayabec and La Vieille platforms corresponds to the peak of the first shallowing phase in the Gaspé Belt after the Taconian orogeny. The platforms, with their reefs, grew during a period of sea-level stability from the earliest to late Wenlockian. The reefs were killed by an influx of deeper water siliciclastic sediments during a late Wenlockian transgression.

scholarly journals New ridged, conical, fissiculate blastoid from the Permian of Timor

2013 ◽  
Vol 87 (6) ◽  
pp. 1071-1076
Author(s):  
James Sprinkle ◽  
Johnny A. Waters
Keyword(s):  
Twentieth Century ◽  
New Genus ◽  
Morphological Features ◽  
Rugose Coral ◽  
The Family

Permian rocks from the Indonesian island of Timor contain an abundant and diverse pelmatozoan echinoderm fauna that was extensively monographed in the first half of the twentieth century. Recent collections have produced specimens of Corrugatoblastus savilli, n. gen. n. sp., the first new genus of blastoid described from Timor in 70 years. Corrugatoblastus savilli is a ridged and furrowed, conical, fissiculate blastoid with a highly unusual thecal morphology mimicking a small, solitary, rugose coral. We have placed C. savilli in the Family Codasteridae, although it has several morphological features that are unique when compared to other genera in the family and to other blastoid genera regardless of familial assignment.

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